docs: Removed statement that ART does not implement compacting garbage collection. bug: 18181075
docs: Removed statement that ART does not implement compacting garbage collection.
bug: 18181075

Change-Id: Ibbb20604595a6740d19ec1d887854d60fb9d797b

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base